/*
 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.eclipse.imagen.media.opimage;

import java.awt.Rectangle;
import java.awt.image.ColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.awt.image.SampleModel;
import java.awt.image.WritableRaster;
import java.util.Map;
import org.eclipse.imagen.ImageLayout;
import org.eclipse.imagen.PointOpImage;
import org.eclipse.imagen.RasterAccessor;
import org.eclipse.imagen.RasterFactory;
import org.eclipse.imagen.RasterFormatTag;
import org.eclipse.imagen.media.util.ImageUtil;
import org.eclipse.imagen.media.util.JDKWorkarounds;

/// Testing
/// import org.eclipse.imagen.JAI;
/// import org.eclipse.imagen.TiledImage;

/**
 * An <code>OpImage</code> implementing the "conjugate" operation as described in <code>
 * org.eclipse.imagen.operator.ConjugateDescriptor</code>.
 *
 * <p>Note that this operation requires a signed destination image so that the SampleModel is overriden to force byte
 * and unsigned short types to short and integer, respectively.
 *
 * @since EA4
 */
final class ConjugateOpImage extends PointOpImage {

    /** Force the destination image to have a signed data type. */
    private static ImageLayout layoutHelper(ImageLayout layout, RenderedImage source) {
        // Create or clone the layout.
        ImageLayout il = layout == null ? new ImageLayout() : (ImageLayout) layout.clone();

        // Get the reference SampleModel.
        SampleModel sm = il.getSampleModel(source);

        // Get the data type.
        int dataType = sm.getTransferType();

        // Determine whether the destination requires a different data type
        // and set it if so.
        boolean createNewSampleModel = false;
        if (dataType == DataBuffer.TYPE_BYTE) {
            dataType = DataBuffer.TYPE_SHORT;
            createNewSampleModel = true;
        } else if (dataType == DataBuffer.TYPE_USHORT) {
            dataType = DataBuffer.TYPE_INT;
            createNewSampleModel = true;
        }

        // Create a new SampleModel for the destination if necessary.
        if (createNewSampleModel) {
            sm = RasterFactory.createComponentSampleModel(
                    sm, dataType, sm.getWidth(), sm.getHeight(), sm.getNumBands());

            il.setSampleModel(sm);

            // Check ColorModel.
            ColorModel cm = il.getColorModel(null);
            if (cm != null && !JDKWorkarounds.areCompatibleDataModels(sm, cm)) {
                // Clear the mask bit if incompatible.
                il.unsetValid(ImageLayout.COLOR_MODEL_MASK);
            }
        }

        return il;
    }

    /**
     * Constructs a ConjugateOpImage. The image dimensions are copied from the source image. The tile grid layout,
     * SampleModel, and ColorModel may optionally be specified by an ImageLayout object. The destination data type must
     * be the smallest appropriate signed data type.
     *
     * @param source a RenderedImage.
     * @param layout an ImageLayout optionally containing the tile grid layout, SampleModel, and ColorModel, or null.
     */
    public ConjugateOpImage(RenderedImage source, Map config, ImageLayout layout) {
        super(source, layoutHelper(layout, source), config, true);

        // Set flag to permit in-place operation.
        permitInPlaceOperation();
    }

    /**
     * Calculates the complex conjugate of the source image. The sources are cobbled.
     *
     * @param sources an array of sources, guarantee to provide all necessary source data for computing the rectangle.
     * @param dest a tile that contains the rectangle to be computed.
     * @param destRect the rectangle within this OpImage to be processed.
     */
    protected void computeRect(Raster[] sources, WritableRaster dest, Rectangle destRect) {
        // Retrieve format tags.
        RasterFormatTag[] formatTags = getFormatTags();

        Raster source = sources[0];
        Rectangle srcRect = mapDestRect(destRect, 0);

        RasterAccessor srcAccessor = new RasterAccessor(
                source, srcRect, formatTags[0], getSourceImage(0).getColorModel());

        RasterAccessor dstAccessor = new RasterAccessor(dest, destRect, formatTags[1], getColorModel());

        switch (dstAccessor.getDataType()) {
            case DataBuffer.TYPE_SHORT:
                shortLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_INT:
                intLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_FLOAT:
                floatLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_DOUBLE:
                doubleLoop(srcAccessor, dstAccessor);
                break;
            case DataBuffer.TYPE_BYTE:
            case DataBuffer.TYPE_USHORT:
            default:
                throw new RuntimeException(JaiI18N.getString("ConjugateOpImage0"));
        }

        // If the RasterAccessor object set up a temporary buffer for the
        // op to write to, tell the RasterAccessor to write that data
        // to the raster no that we're done with it.
        if (dstAccessor.isDataCopy()) {
            dstAccessor.clampDataArrays();
            dstAccessor.copyDataToRaster();
        }
    }

    private void shortLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        short dstDataArrays[][] = dst.getShortDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        short srcDataArrays[][] = src.getShortDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            boolean isRealPart = k % 2 == 0;
            short dstData[] = dstDataArrays[k];
            short srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            if (isRealPart) { // real part: copy value
                for (int j = 0; j < dheight; j++) {
                    int srcPixelOffset = srcScanlineOffset;
                    int dstPixelOffset = dstScanlineOffset;
                    for (int i = 0; i < dwidth; i++) {
                        dstData[dstPixelOffset] = srcData[srcPixelOffset];
                        srcPixelOffset += srcPixelStride;
                        dstPixelOffset += dstPixelStride;
                    }
                    srcScanlineOffset += srcScanlineStride;
                    dstScanlineOffset += dstScanlineStride;
                }
            } else { // imaginary part: negate value
                for (int j = 0; j < dheight; j++) {
                    int srcPixelOffset = srcScanlineOffset;
                    int dstPixelOffset = dstScanlineOffset;
                    for (int i = 0; i < dwidth; i++) {
                        dstData[dstPixelOffset] = ImageUtil.clampShort(-srcData[srcPixelOffset]);
                        srcPixelOffset += srcPixelStride;
                        dstPixelOffset += dstPixelStride;
                    }
                    srcScanlineOffset += srcScanlineStride;
                    dstScanlineOffset += dstScanlineStride;
                }
            }
        }
    }

    // identical to byteLoops, except datatypes have changed.  clumsy,
    // but there's no other way in Java
    private void intLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        int dstDataArrays[][] = dst.getIntDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        int srcDataArrays[][] = src.getIntDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            boolean isRealPart = k % 2 == 0;
            int dstData[] = dstDataArrays[k];
            int srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            if (isRealPart) { // real part: copy value
                for (int j = 0; j < dheight; j++) {
                    int srcPixelOffset = srcScanlineOffset;
                    int dstPixelOffset = dstScanlineOffset;
                    for (int i = 0; i < dwidth; i++) {
                        dstData[dstPixelOffset] = srcData[srcPixelOffset];
                        srcPixelOffset += srcPixelStride;
                        dstPixelOffset += dstPixelStride;
                    }
                    srcScanlineOffset += srcScanlineStride;
                    dstScanlineOffset += dstScanlineStride;
                }
            } else { // imaginary part: negate value
                for (int j = 0; j < dheight; j++) {
                    int srcPixelOffset = srcScanlineOffset;
                    int dstPixelOffset = dstScanlineOffset;
                    for (int i = 0; i < dwidth; i++) {
                        dstData[dstPixelOffset] = -srcData[srcPixelOffset];
                        srcPixelOffset += srcPixelStride;
                        dstPixelOffset += dstPixelStride;
                    }
                    srcScanlineOffset += srcScanlineStride;
                    dstScanlineOffset += dstScanlineStride;
                }
            }
        }
    }

    private void floatLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        float dstDataArrays[][] = dst.getFloatDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        float srcDataArrays[][] = src.getFloatDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            boolean isRealPart = k % 2 == 0;
            float dstData[] = dstDataArrays[k];
            float srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            if (isRealPart) { // real part: copy value
                for (int j = 0; j < dheight; j++) {
                    int srcPixelOffset = srcScanlineOffset;
                    int dstPixelOffset = dstScanlineOffset;
                    for (int i = 0; i < dwidth; i++) {
                        dstData[dstPixelOffset] = srcData[srcPixelOffset];
                        srcPixelOffset += srcPixelStride;
                        dstPixelOffset += dstPixelStride;
                    }
                    srcScanlineOffset += srcScanlineStride;
                    dstScanlineOffset += dstScanlineStride;
                }
            } else { // imaginary part: negate value
                for (int j = 0; j < dheight; j++) {
                    int srcPixelOffset = srcScanlineOffset;
                    int dstPixelOffset = dstScanlineOffset;
                    for (int i = 0; i < dwidth; i++) {
                        dstData[dstPixelOffset] = -srcData[srcPixelOffset];
                        srcPixelOffset += srcPixelStride;
                        dstPixelOffset += dstPixelStride;
                    }
                    srcScanlineOffset += srcScanlineStride;
                    dstScanlineOffset += dstScanlineStride;
                }
            }
        }
    }

    private void doubleLoop(RasterAccessor src, RasterAccessor dst) {
        int dwidth = dst.getWidth();
        int dheight = dst.getHeight();
        int dnumBands = dst.getNumBands();

        double dstDataArrays[][] = dst.getDoubleDataArrays();
        int dstBandOffsets[] = dst.getBandOffsets();
        int dstPixelStride = dst.getPixelStride();
        int dstScanlineStride = dst.getScanlineStride();

        double srcDataArrays[][] = src.getDoubleDataArrays();
        int srcBandOffsets[] = src.getBandOffsets();
        int srcPixelStride = src.getPixelStride();
        int srcScanlineStride = src.getScanlineStride();

        for (int k = 0; k < dnumBands; k++) {
            boolean isRealPart = k % 2 == 0;
            double dstData[] = dstDataArrays[k];
            double srcData[] = srcDataArrays[k];
            int srcScanlineOffset = srcBandOffsets[k];
            int dstScanlineOffset = dstBandOffsets[k];
            if (isRealPart) { // real part: copy value
                for (int j = 0; j < dheight; j++) {
                    int srcPixelOffset = srcScanlineOffset;
                    int dstPixelOffset = dstScanlineOffset;
                    for (int i = 0; i < dwidth; i++) {
                        dstData[dstPixelOffset] = srcData[srcPixelOffset];
                        srcPixelOffset += srcPixelStride;
                        dstPixelOffset += dstPixelStride;
                    }
                    srcScanlineOffset += srcScanlineStride;
                    dstScanlineOffset += dstScanlineStride;
                }
            } else { // imaginary part: negate value
                for (int j = 0; j < dheight; j++) {
                    int srcPixelOffset = srcScanlineOffset;
                    int dstPixelOffset = dstScanlineOffset;
                    for (int i = 0; i < dwidth; i++) {
                        dstData[dstPixelOffset] = -srcData[srcPixelOffset];
                        srcPixelOffset += srcPixelStride;
                        dstPixelOffset += dstPixelStride;
                    }
                    srcScanlineOffset += srcScanlineStride;
                    dstScanlineOffset += dstScanlineStride;
                }
            }
        }
    }

    //     public static void main(String[] args) {
    //         int[] dataTypes =
    //             new int[] {DataBuffer.TYPE_BYTE, DataBuffer.TYPE_SHORT,
    //                            DataBuffer.TYPE_USHORT, DataBuffer.TYPE_INT,
    //                            DataBuffer.TYPE_FLOAT, DataBuffer.TYPE_DOUBLE};

    //         for(int dt = 0; dt < dataTypes.length; dt++) {
    //             WritableRaster wr =
    //                 RasterFactory.createBandedRaster(dataTypes[dt],
    //                                                  5, 5, 4, null);
    //             int k = 0;
    //             for(int y = 0; y < 5; y++) {
    //                 for(int x = 0; x < 5; x++) {
    //                     for(int z = 0; z < 4; z++) {
    //                         wr.setSample(x, y, z, k++);
    //                     }
    //                 }
    //             }
    //             SampleModel sm =
    //                 RasterFactory.createBandedSampleModel(dataTypes[dt],
    //                                                       2, 2, 4, null, null);
    //             TiledImage ti = new TiledImage(0, 0, 5, 5, 0, 0, sm, null);
    //             ti.setData(wr);
    //             RenderedImage ri = JAI.create("conjugate", ti);
    //             Raster r = ri.getData();
    //             for(int y = 0; y < 5; y++) {
    //                 for(int x = 0; x < 5; x++) {
    //                     for(int z = 0; z < 4; z++) {
    //                         System.out.print(r.getSampleDouble(x, y, z)+" ");
    //                     }
    //                     System.out.print(" : ");
    //                 }
    //                 System.out.println("");
    //             }
    //             System.out.println("");
    //         }
    //     }
}
